ABSTRACT
The isolation of Moraxella catarrhalis in the nasopharynx of healthy subjects indicates that there is a potential risk for respiratory infections; especially otitis media; due to this organism. The carrier rates of M. catarrhalis in the nasopharynx of patients with illness other than the respiratory tract were determined. One hundred and twenty patients of all ages were screened. The patients' ages ranged between 18 months to 72 years (mean 31.4 years). There were 58 males and 54 females with male to female sex ratio of 1 :0.93 M. catarrhalis was isolated in 8 (7.2 percent) patients either in pure culture or mixed with other bacteria. The highest isolation was found mixed with S. pneumoniae which was in 3 (2.7 percent) cases. Fifty percent of the M. catarrhalis isolates were Beta - lactamase produres as detected by the chromogenic cephalosporin method using nitrocifin discs. A high percentage of Beta - lactam producing M. catarrhalis isolates has negative effects in the treatment of Beta - lactam antibiotic sensative respiratory pathogens; since the enzyme destroys the drug before it acts on the target organisms